Offscreen vs Runloop Devboxes

Offscreen

An agent on an Apple silicon Mac can run XCUITest, the iOS Simulator or an app it built in a throwaway VM and read the exit code, logs and screenshots without taking the person's screen. The project is six days old at v0.0.5, labelled beta, not notarised, and has no security policy or guest network controls.

Runloop Devboxes

Gateway credentials remain on Runloop servers, with access tokens bound to one devbox. Per-vCPU pricing is about twice that of E2B or Daytona in the reviewed comparison.

Offscreen

1. Read .offscreen.toml before running anything and use its project key and task names. Don't guess them
2. Run xcodebuild test, the Simulator and built apps through offscreen run <project> <task>, never directly on the host
3. Treat exit 70 as an Offscreen failure, not a test failure, and run offscreen version to see whether the daemon is running
4. Ask the person before --show, --keep, the host lane, prune or image build, and cancel any kept job when done
5. Read screenshots and .xcresult bundles from the directory offscreen artifacts <job> prints

Runloop Devboxes

1. Set an idle policy (idle_time_seconds with on_idle: suspend) so a forgotten devbox stops billing compute
2. Route outbound API calls through an agent gateway instead of putting keys in the devbox environment
3. Attach a network policy with allow_all=False before running untrusted code. Egress is open by default
4. Restart background services after every resume. Nothing in memory survives
5. Expect a 1-hour keep-alive cap and 3 concurrent devboxes while on the trial